Circuit breaker



Oct. 12, 1954 H. J. LINGALETAL CIRCUIT BREAKER 6 Sheets-Sheet Filed Oct. 51, 1952 INVENTORS Harry J.Lingo| ond WITNESSES:

- mf/z Jerome Sandin. @Q82 9J L@ y ATTORNEY Oct. 12, 1954 H. J. LINGAL Erm. 2,691,709

CIRCUIT BREAKER Filed Oct. 31, 1952 6 Sheets-Sheet 2 WITNESSES: INVENTORS d f Harry J.Lngolon Jerome Sondin.

Oct. 12, 1954 H. J. UNG/u. ETAL 2,691,709

CIRCUIT BREAKER Filed Oct. 31, 1952 6 Sheets-Sheef' BYJerome Sondin. mb. @5% q//LW ATTORNE H. J. LINGAL ET AL Oct. 12, 1954 CIRCUIT BREAKER '6 Sheets-Sheet 4 Filed Oct. 31, 1952 Fig.5.

INVENTORS Horry J. Lngol and Jerome Sondin.

$4/ L94 ATTORNEY Oct. 12, 1954 H. J. I INGAL rrr/u.. 2,691,709

CIRCUIT BREKER 40 |00 400 :00o 4000 |0000 303D U Y 339 HarryrJ. Lingo! 0nd Jerome Sondin.

Oct. l2, 1954 H. J. LING/u. ETAL CIRCUIT BREAKER 5 Sheets-Sheet '6 Filed om. s1, 1.952

INVENTCRS Hurry J. Lingol ond BY VJerome Sondin.

wlTNEssEs:

ATTORNEY Patented Oct. 12, 1954 CIRCUIT BREAKER Harry J. Lingal and Jerome Sandin, Pittsburgh,

Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, la., a corporation of Pennsylvania Application October 31, 1952, Serial No. 317,952

Claims.

This invention relates to circuit breakers and more particularly to circuit breakers of the type used to control light to moderate power distribution circuits.

An object of the invention is to provide a circuit breaker embodying a trip device which is selectively responsive at different time delays to overload currents of different value.

Another object of the invention is to provide a circuit breaker embodying a trip device including a time-delay device of the fluid dashpot type in which the time delay in the operation of the trip device is controlled by admitting fluid to the dashpot at different rates.

Another object of the invention is to provide a circuit breaker having an electroresponsive trip device embodying a time-delay device of the uid dashpot type in which time delays of dilerent duration are effected in the operation of the trip device by the operation of a single valve means to admit fluid to the dashpot at diierent rates.

A further object of the invention is to provide a circuit breaker embodying a trip device in which the operating parts are mounted on a base which is readily removable Without disengaging any connection.

Another object of the invention is to provide a circuit breaker embodyinga trip device in which the operating parts are mounted on a separate base which is removable without destroying the calibration of the device.

Another object of the invention is to provide a circuit breaker embodying a novel trip device comprising a plurality of separable insulating housing units including an energizing coil insulated irom other parts of said trip device by parte of adjacent housing units.

Another object oi the invention is to provide a circuit breaker embodying a trip device in which the operating parts are mounted on a removable base to facilitate assembly, calibration and adjustment.

The invention both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of a preferred embodiment thereof, when read in conjunction with the accompanying drawings.

In said drawings:

Figure l is a side elevational view, partly in section, ci a circuit breaker embodying the principles of the invention.

Fig. 2 is an enlarged sectional view through the trip device taken substantially along line II-II of Fig. 3 and showing the magnet structure and the time-delay device.

Fig. 3 is a top plan View of the armature structure and the time delay device shown in Fig. 4.

Fig. 4 is a iront elevational view of the timedelay device including the tripping armature with the intermediate housing, the magnet yoke and the coil removed.

Fig. 5 is a left elevational of the mechanism shown in Fig. 4 showing the adjusting means.

Fig. 6 is a vertical sectional view through the valve for controlling the admission of air to the dashpot.

Fig. 7 is a fragmentary sectional View of a part of the structure shown in Fig. 6 but showing a diierent valve member.

Fig. 8 is a detail View, partly in section, showu ing the valve operating armature and the adjusting means for the valve.

Fig. 9 is a schematic diagram showing the range of adjustments of the trip device.

Fig. l0 is an elevational view oi a part of the trip device showing the scale plate and the several adjusting knobs of the trip device when ar ranged for service as a load breaker.

Fig. 11 is a View similar to Fig. 10 but with the trip device arranged for service at another point in the distribution system.

Fig. 12 is an extended perspective view of the elements of the trip device.

Fig. 13 is a schematic diagram ci a group of circuit breakers in a typical distribution system.

Referring to Fig. 1 of the drawings, the circuit breaker includes a plurality of pole units each comprising a contact structure indicated generally at H and an overcurrent trip device indicated generally at i3. The contact structure and the trip device for each pole unit are mounted on a separate insulating base l5 which is rigidly secured to a metal supporting panel i'l. Since the pole units are alike, only the center pole unit is illustrated and described herein.

The contact structure il comprises stationary main and arcing contacts i9 and 2 i, both secured to the inner end of a terminal conducting bar 23, and cooperating movable main and arcing contacts 25 and 21. The movable contacts are rigidly secured t0 a contact-carrying member 29 pivotally mounted by means of a pivot pin 3l and a U-shaped switch arm 33 which, in turn, is pivotally supported by pivot means 35 and brackets 3l rigidly mounted on the base i5.

The movable contact-carrying member 29 is electrically connected by means of a flexible conductor 39 to the energizing coil of the trip device I3. A spring 4I compressed between the member 29 below its pivot 3| and the insulating base I5 provides contact pressure in the closed position of the breaker and also biases the movable contact structure in opening direction.

The movable contact structure is normally maintained in the closed contact position by means of an operating mechanism indicated generally at 43 supported in a U-shaped frame 45. The frame 45 is supported on a platform 41 which forms a cross member of a generally U-shaped main bracket comprising a pair of spaced side members 49 rigidly connected at their outer ends by the cross member or platform 41. The platform 41 extends substantially across the width of v the breaker and the side members 49 and is suitably secured to the metal panel I1 on the outside of the two outer pole units of the breaker.

The operating mechanism includes a lever 5I mounted on a pivot pin 53 supported in the side members of the frame 45. The lever 5| carries a rod 55 extending across all of the poles of the breaker and is connected by means of insulating connecting members 51 to the pivot pins 3| in the free ends of the switch arms 33 for the several f poles of the breaker so that upon operation of the rod 55 the movable contacts of all of the poles move in unison.

An operating linkage comprising toggle links 55, 5| and l53 is provided to normally hold the lever 5I and consequently the movable contacts in the closed position and to operate the movable contacts to open and closed positions. The toggle link 59 is pivotally connected to the lever 5I by a pivot 55 and the toggle link 63 is pivoted on a xed pivot 61 supported on the frame 45. The toggle link 9| is pivotally connected to the links 59 and 93 respectively by knee pivots B9 and 1I.

The linkage 59, 6I, 53 comprises two toggles,

one of which 59,15I may be designated as the tripping toggle and the other 6I, 63 as the closing toggle. The tripping toggle 59, 6I is normally slightly `underset above a line through the centers of the pivots 65, 1|, and the closing toggle 6I, `63 is normally underset below a line through the pivots 61, 69. The closing toggle is normally prevented from collapsing downward by a support member 13 pivoted on a pin 15 supported in the frame and having a shouldered portion engaging under the knee pivot 1| of the closing toggle.

The tripping toggle 59, 5I is normally biased in a direction to cause its collapse by a component of the force of the springs 4| which bias the movable contact structures for the three poles of the breaker in opening direction and bias the three connecting members 51 toward the left (Fig. l). The tripping toggle is normally prevented from collapsing by a main latch member 11 pivoted on the pin 53 and connected by a link 19 to the knee pivot 69 of the tripping toggle.

The main latch member 11 is held in latching position by an intermediate latch lever 8| pivoted on the pin 15. The intermediate latch lever .8| at its upper end carries a latch roller 83 engaging the main latch 11 and at its lower end has a latching portion 85 engaging a latch member 81 on a channel-shaped latch 89 pivoted on a pin 9| in the frame 45. A spring 93 serves to bias the latch lever 8| and the latch 89 to their latching positions.

A trip bar 95, extending across all of the poles of the breaker, is rigidly mounted on the righthand end of the channel-shaped latch 89 and is adapted to be actuated to eifect opening of the breaker by the trip device I3 of any one of the poles in a manner to be presently described.

The breaker is tripped open manually by means of a cam member IOI mounted on the inner end of a handle shaft |03 journalled in a bearing |05 mounted in the front piece of the frame 45. The `handle is not shown in the drawings but is rigidly secured to the .outer end of the shaft |03 and biased in both directions to a central position in a well known manner by a spring |01.

Rotation of the handle shaft |03 in tripping direction causes the cam member IBI to engage and actuate the latch member 89 in unlatching direction to unlatch the intermediate latch lever 8|, which, in turn, releases the main latch 11. This permits the tripping toggle 59, 6I to collapse upwardly to effect opening of the breaker contacts. During the collapse of the tripping toggle, a portion |09 of the toggle link 6| engages and actuates the support member 13 to a non-supporting position, thereby freeing the closing toggle 6 I, 53. The closing toggle thereupon collapses downwardly and during its collapse resets and relatches the tripping toggle 59, 6I.

The breaker contacts may now be operated to the closed position by rotating the shaft |03 and the cam I0| in the direction opposite to the tripping direction. This causes the cam IOI to vengage a projection III on the closing toggle link B3 and moves this link counterclockwise about its .pivot 61. This action straightens the closing toggle until the .support member 13 resumes its supporting position below the knee pivot pin 1I of the closing ytoggle 5I, 63. During the closing operation, the link 19 and latch 11 prevents collapse of the tripping toggle 59, 6I which acts as a thrust transmitting means and moves the movable contact structure to the closed position.

The breaker is automatically tripped open by operation of the trip Adevice I3 for any pole of the breaker. The trip device I3 is of the dead front type, that is, the energizing coil is insulated from all other parts of the trip device. This permits adjustments to be made to the trip device with safety and without opening the breaker or deenergizing the .power circuit.

The housing for the trip device comprises three separate yparts each of molded insulating material. The upper part I I3 of the housing supports the magnet yoke |I5 (Fig. 2) and a trip rod .II-1 and insulates Vthe magnet yoke from the energizing coil |I9 (Figs. l and 2) or |20 as shown in Fig. 12. The upper housing I|3 is secured to v.the .base I5 (Fig. 1) by means of a bolt .|2I which passes .through `aligned openings in the base I5, the lower end of the iiexible conductor 39, one end |23 of the energizing coil ||9 and threadedly engages a metal insert |25 (Fig. 2) molded into the housing II3. The other .end |21 of the energizing coil IIE) is secured by means of a .bolt |29 to ,the base I5 and to the inner end of a terminal `conductor I3I.

A center housing portion |33 (Figs. 1 and 2) of molded insulating material is secured by means of screws |35 (only one being shown) to the upper vhousing VI I3 and is rigidly secured to the base I5 by means of a bolt I 31 which extends through `an opening in the base I5 and threadedly engages a metal insert |39 (Fig. 2) molded in the housing |33.

Supported in the upper housing II3 is the U- shaped laminated vmagnet yoke I5 having its legs 43 and |45 extending downwardly through openings in the upper housing I3 and corresponding openings in the center housing portion |33. The

center housing |33 has an annular projection |51 (Figs. 2 and 12) surrounding the leg |45 of the magnet yoke and the projection |41 extends upwardly in nested relation with an annular flange |55 of the upper housing ||3 to insulate the leg |35 of magnet yoke I |5 from the energizing coil i9. An arcuate flange |5| on the upper housing H3 cooperates with an arcuate portion |53 oi the center housing |33 to insulate the leg |43 of the magnet yoke from the energizing coil H5. The top portion (Fig. 2) of the magnet yoke ||5 rests in a channel formed by side portions |55 of the upper housing H3.

The magnet yoke ||5 is supported and located in the housing by surfaces |51 and |59 and |55 on the center housing |33 and by an angular surface |51 on the upper housing H3. The magnet yoke ||5 is nrst assembled in the upper housing and the upper and center housings ||3 and |35 are then secured together by the screws |35 one of which is shown in Fig. 1. This forces the surface |5| against the beveled corner of the magnet yoke i i5 and seats the yoke against the surfaces |51, |55 and |59 of the center housing |33 thus rigidly holding the magnet yoke in its proper position relative to the housing and the other parts of the trip device.

Mounted on the bottom of the center housing |55 and secured thereto by means of screws |63 (Figs. i and 3) is a base or support |55 of molded insulating material on which are mounted the other parts of the trip device and the time delay device. Secured to the base |55 by means of screws |55 (Figs. 2 and 3) is a diaphragm clamp and armature support member |1| of molded in- Sula-ting material. spaced members |13 molded integral with the member |1| extend upwardly therefrom and are joined by an integral cross member (Fig. 2).

As shown in Figs. 4 and 5, all of the parts illustrated as mounted on the base |55 are assembled thereon before the member is mounted on the center housing member |33 (Figs. 1 and 2). These parts include a main armature |11 for cooperating with the magnet yoke ||5 (Fig. 2). rThe main armature |11 is of laminated construction and has a bearing sleeve |18 mounted therein and a pin |19 extends therethrough (Figs. 4 and 5). The ends of the pin |19 are disposed in recesses |8| formed in the upper ends of the spaced members |13. When assembled in the lower support member the armature |11 is biased upwardly, biasing the ends of the pin |19 into the recesses |3| and retained in the position shown by a spring |83 (Fig. 2) compressed between the cross members |15 and the bottom surface of the armature. The spring |83 engages a spring guide |85 on the cross member |15 and a spring guide |51 on 'the armature.

Referring to Fig. 12 which comprises an eX- tended view of the several elements of the trip device, it would be seen that the outer laminations |55 of the magnet yoke ||5 extend downwardly from the lower end of the leg |45 of the yoke and are provided with recesses |83 therein. After the magnet yoke ||5 is inserted into the upper housing member ||3 and this member is attached to the center housing member |33 with an energizing coil |29 between the upper and center housing members, the base |55 with all of the parts (Fig. 4) mounted thereon is inserted upwardly into the center housing portion |33 and is secured thereto by the screws |63.

As the bottom assemblage of parts (Fig. 4) is vplaced in position .in the center housing |33,

bushings |95 (Figs. 2, 3, 4) mounted on the bearing |13 and disposed one on each side of the armature |11 engage the recesses |35 in the outer laminations of the magnet yoke ||5. The base |55 is moved into the center housing member |33 slightly beyond the point where the bushings |55 engage the recesses |35. This causes the ends of the pin |15 to separate slightly from the upper walls of the recesses |8| in the members |13, slightly compressing the spring |53 and accurately locates the armature |11 relative to the magnet yoke ||5 and the armature, when actuated, will cause the bearing sleeve |18 to pivot in the bushings |55.

As seen in Fig. 2 when the lower assemblage of parts is placed in position and the bushings |55 are seated in the recesses |88, an arcuate surface |52 on the armature |11 adjacent the pivoted end thereof cooperates with an arcuate surface |55 on the lower end of the leg |55 of the magnet yoke to provide a constant predetermined air gap between the pivoted end of the armature and the magnet yoke in all positions of the armature.

The armature |11 is actuated to effect tripping of the breaker under the control of a time delay device |35 (Fig. 2) which comprises generally a flexible diaphragm |5| and a valve device |93 (Fig. (i) for admitting air to the Space pelow the diaphragm at various rates. The flexible diaphragm |5| is disposed in a chamber |95 formed in the hase |55. The outer edge of the diaphragm is clamped between the rim of the member |1| and the base |55 with a. sealing gasket disposed between the diaphragm and the base |55. The central portion of the diaphragm |9| is clamped between upper and lower clamp members |91 and |55, respectively, the lower clamp member |59 having a central threaded stud 20| extending upwardly through an opening in the upper clamp member. A nut 253 is threaded onto the stud 25| and securely clamps the parts together. The armature |11 is connected to the diaphragm by means of a linkage indicated generally at 255 (Fig. 2) which comprises a pair of spaced links 251 (only one being shown) disposed one on each side of an ear 259 on the armature and pivotally connected thereto means of a pin 2 i. A single link 2 3 disposed between the links 231 is pivotally connected by means of a pin 2|5 to the bifurcated upper end of the stud 29 I. The link 213 carries a pin 2 1 which extends laterally on both sides thereof through slots 219 (only one being shown) in the links 251. The links 201 at their ends adjacent the diaphragm are provided with retaining lugs 22| and a coil spring 223 surrounding the linkage is compressed between spring retainers 225 supported on the pin 2 1 and the lugs 22| with a predetermined initial compression. Guide links 221 (Figs. 2 and 3) having one end pivoted on a fixed pivot pin 229 supported in spaced bosses 25| formed on the base of the member |1| are pivotally connected at their other ends to the pin 2|5 which connects the linkage 555 to the stud 25| to guide the movement of the diaphragm.

A U -shaped follow lever 233 (Figs. 2, 3, 4. and 5) comprising spaced levers 235 joined at one end by an integral yoke portion 231 straddles the armature |11 and is pivotally supported on opposite sides of the armature on the pin |19. Each of the levers 235 has a depending portion 235 formed inwardly toward each other below the armature |11 (Fig. 5) and the lower ends of the portions 235 rest on the pin 2|1 (see also Fig. 2), so that upward movement of the pin 2|1 causes acum-co9 vclockwise movement of the follow lever 233 about the pin |19 to Ieffect tripping operation of the trip rod |1.

The trip rod ||1 is rigidly mountedon the yoke portion 24| of an .inverted U-shaped member 243, the legs 245 of which straddle the leg |143 of the magnet yoke l5. The member v24.3 is disposed for vertical movementand is guided .by pins 241 projecting from opposite sides of the leg y|03 Yof the ymagnet -yoke .engaging velongated slots 249 .in the legs 245 of the U-shaped members 243. Ears 25| formed outwardly-from the lower lends ofthe legs 245 are disposed inthe path of rupward movement of the follow levers 235 (see IFig.5) so that actuation of the follow levers 235 causes the free ends of the levers 235 to engage the earsf25| and move .the member 243 .and the trip rod |;|1 upwardly .to cause a thimble 252 thereon to engage and .actuate the trip bar 95 (Fig. l) and trip the breaker.

'I'he rate of tripping movement of the armature |11 and the follow llever 233 is controlled by the movement of the diaphragm |9| which, in turn, iscontrolled by the rate of admission of air to the chamber |95 (Fig. 2) below the diaphragm. Air is admitted to the chamber .|195 upon upward movement of the diaphragm `by vmeans of Athe valve device |93 (Figs. 1, 3, 4 and 6). As best shown in Fig. 6, the valve A|93 comprises a valve insert 253 disposed in anopemng 255 inthe base |65 and held rmly in place by a plug 251 threaded into a cylindrical projection 259 extending downwardly from the base |65. A piston valve 26| is disposed in the bore of the valve insert 259 and is biased upwardly by a spring 263. A portion 265 of the diaphragm clamp member |1| i'its over a projection 261 of the base 4|65 vand a valve operating rod 269 extends through openings in the portion 265 and projection 261 and has a tapered lower end seated in a conical opening in the valve 26| to operate vthe piston valve 26|. A plurality of openings 21| inthe top of the portion 265 admits air through a filter 213 anda central opening in the projection 261 to the upper end of the valve 26 I.

An annular -groove 215 about the midportion of the Valve -insert 253 communicates by means of -an oriiice A211 in the valve insert to :the ybore of the insert and also communicates by means of a passage 219 in the base |65'tothe chamber |95 .below the diaphragm |9|. Thus when the armature |11 (Fig. 2) acting through the linkage A205 moves the diaphragm |9| upwardly, .air will .be admitted to the chamber |95 through the openings 21|, lter 213, the central opening in the projection 261, through the space between the valve 26| and the bore of the insert 253, passages 211, groove 215 and the passage 219 to the chamber |95.

The amount of time delay provided in the operation of the trip device to trip the breaker is determined by the rate of flow of air past ythe piston valve 26|. The rate of flow of .air is determined by the distance the air is required to flow past the piston valve 26|. By varying the clistance the air has to flow past the piston valvethe rate of ilow of the airis varied, which varies the amountof time delay introduced into'tripping action of the device. The distance the air is required to `ilow past the valve 26| is varied by varying the position of the valve relative to the orifice 211 in the insert253.

The means for varying the position of the valve 26| comprises a channel-shaped lever i281 (Figs. L2, 3, 4, J and 6) pivotally mounted on a pin 283 supported in a projection 285 .of the member |1|.

At 'its right-hand end (Figs. 3 and 4) the lever 28| is provided with .a conical depression '281 in which is seated a conical surface 29| of a collar 293 secured toithe valve rod 269. As shown in Fig. 5, theleft-hand end .of the lever 28| has a rounded .portion 295 which is biased by the valve spring 2,63 (Fig. 6) into engagement with an angular portion `291 or a bracket 299. The portion 291 yof the bracket threadedly engages a screw 30| (Fig. 5), `rotatably mounted in the base of the lower housing |65. The screw 30| has a knob 303 secured to its lower end below the housing member |65 and is retained in place by a spring washer 305 engaged in 4a groove in the screw just above thebase |65.

-By rotating the knob 303 and consequently the screw 30| the bracket 299 is movedup-ordown on the screwdepending on the direction of rotation of the knob. This rotates the lever 28| which, through the engagement of the conical depression 281 (Fig. 6) thereon with the valve rod 269, positions the valve rod vand the valve 26| accordingly. With the valve 26| in the position in which it is shown in Fig. 6 a relatively long time delay is `provided in the operation of the trip device.

The valve 26| is also operated to full open position to provide instantaneous tripping. The valve (26| is operated to full open position by a secondary armature 301 (Figs. 2, 3, 4 and 5). The armature 301 is generally U-.shaped and the two legs309 thereof are pivotally supported in grooves 3|| Ain the upper ends of the adjusting screw 30| and the upper yend of a stud 3|3 (Figs. 3 and 5) rigidly mounted in the base |65. As best seen in Fig. 2, the armature 301 adjacent its right-hand end is provided with a clearance opening 3|5 for the spring |83 and the spring guide |85, the armature 301 in its retracted position resting on the cross member |15 of the armature support |13. The armature 301 is connected to the lever 28| at the .leftof the pivot pin 283 (Fig. 5) by means of a spring 3.|1 so that upon operation of the armature 301 in a counterclockwise direction (Figs. zand 4) the lever 28| -will be rotated clockwise (Fig. 5) to move the valve 26| (Fig. 6) to its open position, this movement of the lever 28| .being limited by engagement of the valve element 26| with the bottom of the opening in plug 251. When the valve 26| (Fig. 6) is thus moved downwardly it opens the previously described passages and permits a free flow of .air to the chamber so that the trip device functions instantaneously to trip the breaker.

The main armature |11 is biased to its unattracted position by means of a spring 3 9 (Figs.

.2 and 5) having one end connected to a projection 32| on the end of the armature and the other end connected to an adjustable member 323. The member 323 threadedly engages a screw 325 mounted for rotation in the base |65 .and having an insulating knob 321 secured to the .lower end thereof below the base, the screw 325 being held in place by -a spring washer 329 engaging a groove in thescrew just above the base. By rotating the screw 325 the member 323 travels xup ordown .the screw depending upon the direction of rotation of the screw, thus varying the tension -of the spring which varies the magnitude of overload current required to pick-up the armature |11.

'Ihe pick-.up point `for the lsecondary or instantaneous armature 301 may be similarly ad- `justed. vThe armature 301 is biased to its unattracted jposition (Figs. 2, 4: and 5) by means .of a

9 spring 333 (Figs. 3, 4 and 5) having one end connected to the armature and the other end connected to an adjustable member 335 threadedly engaging a screw 331 rotatably mounted in the base |55. The screw 331 has a knob 339 secured to the lower end thereof and is held in place by a spring washer 311| engaging a groove in the .screw 331 just above the base |65. Rotation of the screw 331 by the knob 333 moves the member 335 up and down according to the direction the screw is turned to vary the tension of the spring 333 which varies the pick-up point of the armature 301.

The adjustable members 293, 323 and 335 respectively are provided with indicating means comprising projections 343, 345 and 351 (Figs. 3 and 5) which engage vertical slots 355i (Fig. in an index plate 35| supported between. the center housing |33 and the lower housing Q55 (see also Fig. 10).

The trip device just described will trip the circuit breaker instantaneously in response to overload currents above a predetermined value and after a time delay on overload currents below the predetermined value. This tripping arrangement is used on the load breakers oi a distribution system to protect the load. However, the feeder breaker in such a system should not trip instantaneously in order to give the load breaker time to trip out and clear the fault. For this reason the feeder breakers of the sys tem are provided with a short time delay trip for the higher overload currents and a long time delay for the lower overload currents.

Figs. '1 and 8 illustrate the trip device arranged ior long time delay and short time delay tripping. This is effected by replacing the valve element 251 (Fig. 6) with a valve element 353 (Fig. '1) of slightly different form and providing a bracket 355 (Fig. 8) and adjusting screw 351 for controlling the amount of movement of the valve element 353. The adjusting screw 351 is mounted for rotation in the base |55 and. has an insulating knob 353 fixed to the lower end thereof below the housing. A. spring clip 33| engages a groove in the screw above the housing base to hold 'the screw in position. The screw 351 is mounted in an opening 333 (Fig. 3) in the base of the housing member |55 between the long time delay adjusting screw 30| (Fig. 5) and the long time delay pick-up adjusting screw 325. The lower portion of the adjusting screw 351 is threaded. and engages a threaded open.- ing in the lower leg of the bracket 355. The upper end 355 of the screw 351 is of reduced cross-section and passes through a clearance opening in the upper leg of the bracket 355. The reduced portion 355 of the screw 351 is threaded and engages a tapped opening in an indicator 351. The thread on the reduced upper end 355 of the screw 351 has approximately twice the lead as the thread on the lower portion, hence, for one rotation of the adjusting screw the indicating member 351 will move twice the distance as the bracket 355. This makes possible an expanded dial on the index plate 35| and provides a more accurate setting of the short time delay device.

The bracket 355 (Fig. 8) is provided with a portion 333 which extends above the lever 23| to limit the movement thereof and also has a lateral projection 31| which extends; above the angular portion 231 of the long time delay adjusting bracket 239 to limit the adjustment of the latter relative to the Short time delay ad- 10 justing bracket 355. Since the movement of the lever 28| is limited by the bracket 355, the spring 3|1 (Fig. 5) permits full operation of the secondary armature 301 upon energiaation of the electromagnet in response to higher overload currents.

With the valve element 353 (Fig. 1) in the position shown, a long time delay is provided in the operation of the trip device by the restricted passage between the valve element 353 and the bore of the insert 253. The position of the valve element 353 is adjusted in the same manner as the valve element 25| (Fig. 6), that is, by the screw 35| (Fig. 5) and the bracket 233. rIhe upper end of the valve element 353 (Fig. '1) is slightly tapered so that when this element is moved downward by operation of the secondary armature 331 (Fig. 8) acting through the spring 313 and lever 28| a portion of the tapered end of the valve element is positioned opposite the orice '211 thus permitting a free ow of air to the chamber |95 to provide the short time delay action but not suicient to effect instantaneous tripping. 'The amount of downward movement of the valve element 353 (Fig. '1) is controlled by the lever 28| (Fig. 8) striking the projection 359 on the bracket 355. Adjustment of the bracket 355, therefore, varies the extent of downu ward movement of the valve 353 and the amount of the tapered portion of the valve positioned opposite the orifice 211 thus varying the amount of short time delay provided.

Means is provided to exhaust the air from lthe chamber |95 below the diaphragm |51 iol- 'lowing a tripping operation to permit resetting valve 315 is biased upwardly against a valve seat 'in the plug 251 by a very light spring 311 which is retained by an oriced washer 313. The washer 313 is held in position by forming a portion of the plug 251 over against the bottom of the p washer.

After the circuit breaker has been tripped open or if a fault has occurred and cleared before the breaker is tripped, the parts of the trip device are reset by the weight of the armature |11 and the force of the spring 3 9 (Fig. 2) applied to the diaphragm 19| This forces the air from the chamber out through the passage 219 (Fig. 6) through the space 255 between'the lower part of the valve member 253 and the portion 259 of the base, through openings 261i in the bottom of the insert 253, and through an orifice 331 in the plug 251 past the ball valve 315 to atmosphere, the pressure forcing the ball valve 315 open to exhaust the air. When the air has been eX- hausted from the chamber |95 to a predetermined pressure the spring 311 reseats the ball valve to prevent air from entering through the orice 33| upon operation of the trip device.

The herein disclosed circuit breaker is well adapted for the protection of distribution systems. Such systems, a typ-ical distribution system being shown schematically in Fig. 13, are usually protected by a series of breakers including a generator breaker 383, bus tie-in breakers 385, feeder breakers 381, and load breakers 383. The circuit breakers of such a system are usually set for se lective tripping, that is, if a fault should occur at a point in the system, the breaker nearest the fault and on the generator side of the fault should open to clear the fault condition. By assembling the trip device with the long time delay valve structure shown in Fig. 6 and omitting the short time delay adjusting means of Fig; 8 thebreaker is adapted to be used as a load breaker. The load breaker may be adjusted to trip out after a relatively long time delay in response to overload currents up to, for instance, 1000% of normal rated current, and instantaneously in response to overload currents above '1000% of normall rated current or short circuit currents.

For service in other positions of the system, for instance, as a bus tie-in or feeder breaker, the valve element 353 (Fig. 7) in substituted for the valve element 26 I, of Fig. 6 and the short time delay adjusting meansof Fig. 8 is assembled in the trip device. The circuit breaker willthen trip and after a long time delay in response to overload currents, up to, for instance, 50.0% ofnormal rated current and after a relatively short time delay in response to overload currents above 500% of normal rated currents.

The time-currentv requirement of the trip device varies with the position-of thegbreaker in the selective system for which reason a trip device providing a wide range of adjustment is essential.

As illustrated in Fig. 9, the trip device is capable of a wide range of adjustments. Considering first the load breaker, there are three separate adjusting devices all located for ease of accessibility. By way of example'of: the rangeof adjustment, the following have beenl arbitrarily selected for illustrative purpose:

l. Range of long time delay pick-up, from 80% to 160% of coil rating.

2. Range of long time delay from to 25 seconds.

3. Range of instantaneous pick-up, from 500% to 1.500% of coil rating.

When used as a feeder or bus tie-in breaker four separate adjusting devicesv are provided all located for ease of accessibility. The range of adjustment of these devices' are arbitrarily selected as follows:

1. Range of long time delay pick-up, from 80% to. 160% of coil rating,

2. Range of long time delay, from 30 to 60 seconds.

3. Range of short time delay pick-up from 500% to 1000% of coil rating.

4. Range of short` time delay, from 6 to 30A cycles.

Figure 9 graphically illustrates the ranges of the several adjustments of the trip device, the range of adjustments for the load breaker being shown by full lines and for the feeder breaker by dotted lines. Along the left-hand edge of Fig. 9 is indicated the time in seconds-and at the righthand edge is indicated the time in cycles based on 60 cycle frequency. At the bottom is indicated the percent of said rating. The curve A represents the minimum settings of the adjustments for the load breaker, the curve A" representing the minimum settings for the feeder or other breakers. The corresponding maximumsettings are represented by thecurves- B and B'. By adjusting the knob 321 (Figs. 5 and I0) the long time delay pick-up may ber adjusted to pick-up at any point in the band of adjustments dened by curves A and B as indicated at C, that is, by

way of example, between 80% and 160% of coilv rating. Adjusting the knob 303V (Figs. 5 and 10) which controls the position of the valve element 26! (Fig. 6) varies the amount of long timeA delay between 5 and 25 seconds as indicated at Din Fig. 9. As indicated at E (Fig. 9) the instantaneous pick-up point may-be varied between 500% 12 and 1500% of coil rating by adjusting the knob 333 (Figs. 5 and 10) which controls the tension ofthe biasing spring 333 (Figs. 3, 4 and 5) for the secondary armature 30'! which operates the valve 26| (Fig. 6).

When the trip device is arranged for service as a feeder or bus tie-in breaker the range of adjustments is shown by the dotted lines A and B in Fig. 9. The long time delay pick-up is adjusted by the same knob 321 (Fig. 11) and over the same range as the load breaker as indicated at C in Fig. 9. Also the amount of long time delay is adjusted by the knob 303, however, in the case of the feeder breaker this range is between approximately 30 and 60 seconds as indicated at F (Fig. 9). The short time delay pickup is adjusted by the knob 339 (Fig. 11) which adjusts the bias of the biasing spring 333 (Figs. 3, 4 and 5) for the secondary armature 301. As indicated at G in Fig. 9 the short time delay pick-up may be set to pick up between 500% and 1000% of coil rating. The amount of short time delay may be varied between 5 and 30 cycles, as indicated at H, by adjusting the knob 359 (Figs. 9 and 11).

Each of the adjustments may be made by merelyv turning the adjusting knob associated with the particular adjusting device. The adjustments are independent of one another and all of the adjusting knobs are conveniently located. All of the operating parts except the trip rod are mounted on the base |65 which is readily removable so that all of the parts are easily accessible for assembly, checking and adjustment. Series coils of different ratings are readily interchangeable and are fully insulated from the magnetic circuit and from all other parts of the trip device by the insulating housing, thus permitting adjustmentsL to the trip device to be made Without opening the breaker or otherwise deenergizing the power circuit.

While the formr of mechanism shown and described herein is admirably adapted to iulll the objects primarily stated, it is to be understood that it is not intended to confine the invention to the form or embodiment disclosed herein, for it is susceptibleV of embodiment in various forms without departing from the spirit of the invention.

We claim. as our invention:

l. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of an electromagnetic trip device comprising a magnet yoke, an energizing winding, an armature movable upon energization of said winding in response to abnormal circuit conditions, a trip member slidably mounted on said magnet yoke, a time delay element for retarding movement of said armature, a toggle connecting the armature to said time delay element, said toggle having one end connected to said armature and having its knee connected to said time delay element, a member movable by a part engaged and moved with said toggle for engaging and moving said trip member, means defining a passage for admitting air to said time delay element, and a valve disposed in said passage for controlling the rate of admission of air to said time,r delay element to thereby control the. rate of tripping movement of said armature.

2; In a circuit breaker comprising relatively movable contacts and operating means therefor, theY combination of an electromagnetic trip device comprising amagnetk yoke, an energizing winding; an armature movable upon energize.-

tion of said Winding in response to abnormal circuit conditions, a trip member slidably mounted on said magnet yoke, a time delay element for retarding movement of said armature, a toggle connecting the armature to said time delay element, said toggle having one end connected to said armature and having its other end supported on a xed pivot, said toggle having its knee connected to said time delay element, a member engaged .and moved by said toggle for engaging and moving said trip member, means dening a passage for admitting air to said time delay element, and a valve disposed in said passage for controlling the rate of admission oi air to said time delay element to thereby control the rate of tripping movement of said armature.

3. In a circuit breaker comprising relatively movable contacts and operating mechanism therefor, the combination of an electromagnetic trip device comprising a magnet yoke, an energizing coil, an armature movable upon energization of said coil in response to overload currents, a trip member slidably mounted on said magnet yoke, a time delay element comprising a movable abutment for retarding movement of said armaturaa toggle connecting said armature to said abutment, said toggle having one end. connected to said armature and the other end pivoted on a xed pivot, the knee of said toggle being connected directly to said movable abutment, a member engaged and moved by said toggle for engaging and actuating said trip member, means defining a passage for admitting air tosaid movable abutment, and a valve disposed in said passage for controlling the rate of admission of air to said movable abutment to thereby control the rate of tripping movement of said armature.

4. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of an electromagnetic trip device comprising a U-shaped magnet yoke, an energizing coil, a pivoted armature movable upon energization of said coil in response to overload currents, a trip member slidably mounted on one leg of said U-shaped magnet yoke, a time delay element comprising a movable abutment for retarding movement of said armature, a toggle connecting said armature to said abutment, said toggle being operated by said armature and hav- 1 ing a part connected to said movable abutment, a pivoted lever engaged and moved by said toggle for engaging and actuating said trip member, and a valve controlling a passage for admitting fluid to said movable abutment at a predetermined rate to provide a time delay in the operation of said armature.

5. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination or an electromagnetic trip device comprising a magnet yoke, an energizing Winding, an armature movable upon energization of said Winding in response to overload currents, a trip member mounted on said magnet yoke, a time delay element for retarding `movement of said armature, a toggle operable by said armature, a member operable by said toggle for engaging and actuating said trip member, a valve controlling a passage normally 'admitting fluid at a predetermined rate to said time delay element to direct `a predetermined time delay in the operation o said armature, a lever Ifor actuating said valve to increase the rate of admission of fluid to said time delay element to thereby decrease the time delay, and a secondary 14 armature connected to said lever and operable in response to certain overload currents to actuate said lever.

6. In 'a circuit *breaker comprising relatively movable conta'cts and operating -means therefor, the combination of an electromagnetic trip device comprising a magnet yoke, an energizing winding, an armature movable upon energization of said Winding in response to overload currents, a trip member mounted on said magnet yoke, a time delay element for retarding movement of said armature, a toggle operable by said armature, a member operable by said toggle for engaging and actuating said trip member, a valve controlling a passage normally admitting iiuid at a predetermined rate to said time delay element to eiect a predetermined time delay in the ope-ration of said armature, a lever for actuating said valve to increase the rate of admission of uid to said time delay element to thereby decrease the time delay, adjusting means for adjusting the position of said lever to thereby adjust the initial position of said valve and a secondary armature connected to said lever and operable in response to certain overload currents to actuate said lever.

'7. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of an electromagnetic trip -device comprising a magnet yoke, an energizing winding, an armature movable upon energization of said winding in response to overload currents, a trip member mounted on said magnet yoke, a time delay element for retarding movement of said armature, a toggle operable by said armature, a member operable by said toggle Ifor engaging and actuating said trip member, a valve controlling a passage normally admitting iiuid at a predetermined rate to said time delay element to effect .a predetermined time delay in the operation of said armature, a lever for actuating said valve to increase the rate of admission of fluid to said time delay element to thereby decrease the time delay, adjusting means for adjusting the position of said lever to thereby adiust the initial position of sai-d valve, a secondary armature connected to said lever and operable in response to certain overload currents to actuate said lever, and an adjustable stop for limiting the movement of said lever by said secondary armature.

8. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of an electromagnetic trip device comprising a magnet yoke, an energizing coil, an armature movable `upon energizaticn of said coil in response to overload currents, a trip member movable to eiect a tripping operation, a dashpot for retarding tripping operation of said armature, a linkage having one end connected to said armature and the other end pivoted on a xed pivot, said linkage being also connected to said dashpot and being operable by 'said armature, a member operated by said linkage for engaging and moving said trip member, a piston valve controlling a passage for normally admitting fluid to said dashpot, said valve having a normal position in which it admits iiuid -to said dashpot at a predetermined rate to effect a time delay in the operation of said armature and movable to a second position to increase the rate of admission of iluid to said dashpot, a pivoted lever for moving said valve to sai-d second position, and a second armature having a connection with said lever for actuating said lever.

9. In a circuit' breaker comprising relatively movable contacts and operating means therefor, the combination of a trip device comprising separable housing members of molded insulating material, a magnet yoke, an= energized coil, said housing members havingsurfaces a-nd projections molded integral therewith for receiving and supporting said magnet yoke and for insulating said magnet yoke from said energizing coil, a, trip member mounted on said magnet yoke and movable to eiTect a tripping operation, a base member also of molded insulating material removably supported on one of said housing members, a movable armature supported on said base member and biased into-cooperative relation With said magnet yoke, a dashpot mounted on said base member for retarding tripping operation of said armature, a linkage having one end connected tc said armature and the other end pivotally supported on said base member, said linkage being also connected to said dashpot and operable by said armature, a member mounted on said base and operable byv said linkage for engaging and actuating said trip member, a valve mounted in said base member andl controlling a passage for admitting fluid to said dashpot, and said base member and all of said parts supported thereon being removable Without disengaging any connection.

l0. In a circuit breaker comprising relatively movablel contacts. and operating means therefor, the combina-tion of a tripV device comprising separabley housing members of molded insulating material, a U-shaped magnet yoke, an energizing coil, said housing members having surfaces and projections molded integral therewith for receiving and supporting said magnet yoke and for insulating said magnet yoke from said energizing coil, a trip member mounted on said magnet yoke and movable to effect a tripping operation, a base member also of molded insulating material removably supported on one of said housing members, a movable armature supported on said base member and biased into cooperative relation with one-leg of said magnet yoke, a dashpot mounted on said base member for retarding tripping operation of said armature, a linkage having one end connected to said armature and the other end pivotally supported on said base member, said linkage being also connected to said dashpot and operable by said armature, a member mounted on said base and operable by said linkage for engaging and actuating said trip member, a valve mounted in said base member and controlling a passage for admitting fluid to said dashpot,. and saidbase member and al1 of said parts supported thereon being removable without disengaging any connection.

1l. In a circuit breaker comprising relatively movable contacts and operating means therei'or, the combination of a trip device comprising separable housing members of molded insulating material, a U-shaped magnet yoke, anY energizing coil, said housing members having surfaces and projections molded integral therewith for receiving and supporting said magnet yoke and for insulating said magnet yoke from said energizing coil, a trip member mounted on said magnet yoke and movable to eilect a tripping operation, a base member also of molded insulating material` removably supported on one of said housing members, a movable armature supported on said base member and biased into cooperative relation With one leg of said U-shaped magnet yoke, a dashpot mounted on saidbase member for retarding tripping operation of' said armature, a toggle having one end connected to saidV armature and the other end pivotally supported on said base member, said toggle being also connected to said dashpot and. operable by said armature, a member mounted on said base and operable by said toggle for engaging and actuating said trip member, a valve mounted in said base member and controlling a passage for admitting iiuid to said dashpot, and said' base member and all of said parts supported thereon being removable Without disengaging any connection.

l2. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination or' a trip device comprising separable housing members of molded insulating material, a U-shaped magnet yoke supported insaid housing members, an energizing winding, said housing members having recesses and projections completely insulating said trip device from saidv energizing winding, a trip member slidably mounted on one leg of said magnet yoke and movable to effect a tripping operation, a base member also of molded insulating material removably supported on one of said housing members, al movable armature supported on said base and' having pivot means thereon, biasing means biasing said pivot means into cooperative relation with the other leg of said U-shaped magnet yoke, a time delay element including a Chamber for retarding tripping movement oi said armature, a toggle having one end' connected to said armature andv the other end pivotally supported on said base member, said toggle having its knee connected to said time delay element, a member movable by said toggle for engaging and moving said trip member, a valve controlling a passage in said base member for admitting iluid to said chamber, and said base member including all of the parts mounted thereon being separable from said one housing member Without disengaging any connections.

13. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination ofl a trip device comprising separable housing members of molded insulating material', a Ushaped magnet yoke supported in said housing members, an energizing winding, said housing members having recesses andi pro'- jections completely insulating said trip device from said energizing Winding, a trip member slidably mounted on oneV leg of said magnet yoke and movable to' effect a tripping operation, a base member also of molded insulating material removably supported' on one of said housing members, a movable armature supported on' said base and having pivot means thereon', biasing means biasingl said pvot means into cooperative relation with the other leg of said U-shaped magnet yoke, a time delay element including a chamber for retarding tripping movement of said armature, a toggle having one end connected to said armature and the other end pivotally supported on saidr base member, said toggle having its knee connected to said time delay element, a member pivoted on said pivot means and movable by said toggle for engaging and moving said trip member, a valve controlling a passage in said base member for admitting fluid to said chamber, and said base member including all of the parts mounted thereon being separable from said one housing member Without disengaging any connections.

14. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of a trip device comprising separable housing members of molded insulating material, a U-shaped magnet yoke provided with spaced extensions on one leg thereof, said housing members having recesses and surfaces for receiving and supporting said magnet yoke, an energizing winding, said housing members having cooperating projections for insulating said trip device from said energizing winding, a trip member mounted on the other leg of said magnet yoke and movable to effect a tripping operation, a base member also of molded insulating material removably supported on one of said housing members, an armature supported on said base member and having pivot means on one end thereof, a spring biasing said pivot means into cooperative relation with said spaced extensions. a time delay element mounted on said base member including a chamber for retarding tripping movement of said armature, a toggle having one end connected to the other end of said armature and the other end pivotally supported on said base member, the knee of said toggle being connected to said time delay element, a member pivoted on said pivot means and movable by said toggle to engage and move said trip member, a valve controlling a passage in said base member for admitting fluid to said chamber at a predetermined rate to provide a time delay in the tripping movement of said armature, adjusting means mounted on said base member for varying the position of said valve, and said base member together with all of said elements mounted thereon being removable without disengaging any connection.

l5. In a circuit breaker comprising relatively movable contacts and operating means therefor, the combination of an insulating housing comprising a plurality of separable members, a U- shaped magnet yoke one leg of which is provided with spaced extensions having recesses formed thereon, two of said housing members cooperating to rigidly support said magnet yoke, an energizing coil disposed between said two housing members and surrounding said one leg of said magnet yoke, said two housing members having projections thereon cooperating to insulate said magnet yoke from said energizing winding, a trip member, a third housing member supported on one of said two housing members, a movable armature operable upon energizing of said winding in response to overload currents, 'spring means resiliently supporting said armature on said third housing member, pivot means on said armature adjacent one end thereof, said spring means normally biasing said pvot means into engagement with said extensions, a time delay device mounted on said third housing member comprising a movable abutment for retarding tripping movement of said armature, a linkage having one end connected to said armature and the other end pivotally supported on said third housing member, said linkage being connected at a point intermediate its ends to said movable abutment, a member pivotally supported on said pivot means operable by said linkage to engage and actuate said trip member, a valve disposed in a passage in said third housing member for controlling the admission of fluid to said movable abutment to provide a predetermined time delay in the operation of said armature, a valve operating lever pivotally supported on said third housing member for operating said valve to increase the rate of admission of uid to said movable abutment to decrease the time delay in the operation of said armature, a second armature pivotally supported on said third housing member for operating said valve, and said third housing member and the parts mounted thereon being removable without disturbing the calibration of said trip device, and without disengaging any connections.

References Cited in the le of this patent UNITED STATES PATENTS Number 

